1. Field of the Invention
The present invention relates to a data processing apparatus for processing input data according to purposes such as copy, printing, data communication and facsimile communication and for outputting the data.
2. Description of the Related Art
A data processing apparatus such as a multifunction machine provides features including a copier, a printer, a scanner and a facsimile. Data such as an input image or a character is processed according to a desired function and temporarily stored in a hard disk device as storage means. Then, the data is read from the hard disk device for printing on recording sheet as an image or for transmitting over a network or a telephone line. After the data is processed and output, it is erased from the hard disk device.
If a trouble occurs in the hard disk device, data cannot be stored or processed. To address this issue, two hard disk devices are typically used, one of them being for backup. For example, Japanese Patent Laid-Open No. 7-141262 describes that data is compressed in a spare hard disk device and stored with control signals.
However, the hard disk device of the above data processing apparatus stores data only for a time between the data processing and the outputting. That is, the data processing apparatus does not need to back up data. A substitute is needed not to suspend data processing, even if a trouble occurs in a hard disk device.
In the light of the above issues, the present invention aims to provide a data processing apparatus that can process data by using other storage means when a trouble occurs in storage means such as a hard disk device.